1,721,002 research outputs found
Protoilludane sesquiterpenoids as scaffold structures for new antimicrobials against Mannheimia haemolytica
No full textPOTENZIALITÀ TOSSINOGENE DI FUSARIUM spp. ISOLATO DA MAIS E PRODOTTI DERIVATI
No full textNelle principali aree maidicole italiane, in questi ultimi anni, ha destato sempre maggiore preoccupazione il frequente ritrovamento nelle cariossidi di mais di elevate quantità di fumonisina B1, micotossina prodotta principalmente da Fusarium verticillioides (Sacc.) Nirenberg e F. proliferatum (Matsus.) Nirenberg. Lo scopo del presente lavoro è stato quello di valutare la potenziale produzione di fumonisina in vitro da parte di ceppi di Fusarium verticillioides e F. proliferatum isolati da undici campioni costituiti da cariossidi di mais e prodotti derivati. La determinazione del livello di micotossina nei campioni di mais iniziali e nei filtrati colturali dei ceppi saggiati è stata effettuata tramite saggio ELISA. I ceppi di F. verticillioides e F. proliferatum, sono stati successivamente cresciuti in vitro in condizioni adatte alla produzione di fumonisina B1. I risultati ottenuti indicano che tutti gli isolati, indipendentemente dal campione di provenienza, sono tossinogeni, anche se con notevoli variazioni nella quantità di micotossina che ogni individuo saggiato è in grado di sintetizzare. Non è stata evidenziata alcuna correlazione tra quantità di fumonisina ritrovata nel campione iniziale di granella e la produzione in vitro dei ceppi isolati
Potenzialità tossinogene di Fusarium spp. isolato da mais e prodotti derivati
No full textCorn produced in Northem Italy is frequently contaminated by fumonisins, mycotoxins mainly produced by Fusarium verticillioides (Sacc.) Nirenberg and F. proliferatum (Matsus.) Nirenberg. The aim of the present work is the evaluation of the in vitro production of fumonisin B1 by F. verticillioides and F. proliferatum strains isolated from corn kernels and corn dry milling products. Fumonisin contamination in corn products and colture filtrates were evaluated by enzyme-linked immunosorbent assay (ELISA). All the isolated strains of F. verticillioides and F. proliferatum were able to produce very variable mycotoxin amounts in fumonisin-inducing liquid medium. Finally the results showed no relationship between fumonisin contamination in corn and the in vitro fumonisin production by the isolated strain
Effect of seedborne Fusarium verticillioides on corn seed germination and seedling growth
No full textPathogenicity variation in Fusarium verticillioides populations isolated from maize in northern Italy
Full text linkOne hundred and eighty one strains were selected among Fusarium verticillioides populations
isolated from maize samples collected in three fields located in northern Italy. All
the isolates were tested for their pathogenicity on maize seeds by assessing the seed
germination percentages and the percentage infection indexes concerning seed colonization,
radicle decay and coleoptile rot. Fusarium verticillioides strains did not affect seed
germination even in presence of high seed colonization, but showed a variable pathogenic
behavior according to the maize growth stages. Seedborne F. verticillioides population as
well as strains isolated at maturity was effective in seed colonization and in inducing
coleoptile rot, not causing however serious radicle decay. Only populations isolated at
seedling and pre-silking stages showed high radicle decay ability. These results provide
baseline information on F. verticillioides pathogenicity. They constitute an important input
for further investigation of F. verticillioides biology in order to define its evolutionary
potential
A novel secondary metabolite from the Eucalyptus pathogen Mycosphaerella cryptica
Full text linkThe most abundant metabolite of the eucalyptus leaf spot pathogen Mycosphaerella cryptica was
extracted from agar cultures. The structure of the compound was elucidated by detailed studies of
NMR and MS data and by comparison with derivatives. The compound is a previously undescribed
diphenylether structurally related to pannaric acid found in lichens. Culture extracts from another
species of Mycosphaerella isolated from the same environment yielded 5-hydroxymethylfuran-
3-carboxylic acid, a furan acidic compound previously isolated from a basidiomycete fungus. Assays
for bioactivity of these metabolites revealed no evidence for antimicrobial activity. Some phytotoxicity
was seen on newly emerged leaves of Eucalyptus globulus, but not on juvenile or adult leaves, when
treated with either metabolite
Cryphonectric acid and other minor metabolites from a hypovirulent strain of Cryphonectria parasitica
Full text linkInvestigations carried out on secondary metabolites produced in culture by a hypovirulent strain of Cryphonectria parasitica allowed the isolation of several compounds which were characterized by NMR analysis and derivatization reactions. The most abundant metabolite was a new compound, called cryphonectric acid (1). Other metabolites were diaporthin, the only known phytotoxic compound isolated from both virulent and hypovirulent strains of C. parasitica, (+)-orthosporin, and L-p-hydroxyphenyllactic acid (HOPLA). Root growth activity of the purified compounds was evaluated both on tomato seedlings and maize subapical segments
PPARgamma (Peroxisome proliferator-activated receptor gamma) interacts with Sp1 transcription factor on the p21waf1/cip1 promoter region to stimulate its transcription in cladosporol A -treated HT-29 cells
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